Substance misuse in pregnancy

Article Outline

• Abstract
• Introduction
• Case study 1
• Case study 2
• Substance misuse and pregnancy outcomes
• Management of the pregnant drug user
• Antenatal care
• Intrapartum management
• Postpartum management
• Case study 3
  • Case 3
• Women and alcohol
• Alcohol in pregnancy
• Further reading
• Copyright

Abstract 

Substance misuse is a common problem complicating pregnancy and childbirth. Multidisciplinary care is necessary to optimize outcomes because the financial, psychological, social and domestic problems associated with drug misuse are often of greater importance than the physical and medical concerns. A specialist midwife is ideally placed to coordinate the involvement of acute hospital trusts, community midwives, general practitioners, mental health and drug services, social services and sometimes the police. The aim during pregnancy is to engage the client with these multiple agencies, to help bring a degree of order, and to reduce the harm associated with substance misuse. Abstinence and detoxification are not necessarily the priority. This review illustrates the general principles of managing substance misuse in pregnancy using three case scenarios covering both drug and alcohol misuse.

Keywords: alcohol, cocaine, detoxification, fetal alcohol syndrome, neonatal abstinence syndrome, opioid misuse, pregnancy

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Introduction 

Approximately one-third of adults who access drug services are women. These women range in age from their early teens to their mid-40s. Most have had a termination, miscarriage or live birth, and their problem drug use has had serious negative physical, psychological, social, financial or legal consequences for themselves and those around them (Table 1).

Table 1. Common problems associated with substance misuse

Opioids, especially heroin, remain the most commonly used drugs in the UK, though many drug users take combinations of drugs that often include cocaine or crack cocaine. Most problem drug users smoke tobacco and many are heavy users of alcohol and cannabis. Taking drugs in combination greatly increases the unpredictability of their effect on the user, as does injecting them intravenously. This also puts drug users at greater risk of infection with blood-borne viruses (hepatitis A, B and C, HIV). Women are particularly susceptible to substance misuse-related interpersonal issues, trauma and medical problems. They are more likely to have a drug-using partner and more likely to share injecting equipment. Almost one-quarter of female intravenous drug abusers report needle-sharing in the previous month, often with a sexual partner, and may avoid needle exchanges to conceal their drug use.

Many drug users live in disadvantaged communities in conditions of poverty and social exclusion. Many have had difficult childhoods, poor parenting experiences, poor education or significant mental health problems.

To optimize pregnancy outcomes, a multidisciplinary approach is necessary for the care of women who abuse legal (e.g. alcohol) or illegal substances. Specialized medical knowledge is important; however, the skills of the specialist midwife extend beyond this and into liaison between social and psychological support services.

Below are three cases illustrating some of the common issues surrounding the care of pregnant women who are problem substance users. The first two relate to illicit drug use, and the third case, described later, covers alcohol dependency during pregnancy.

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Case study 1 

Marion and her partner had planned this current pregnancy and were known to the specialist midwifery service having accessed it previously for a ‘termination of pregnancy’ referral to the local CASH (contraception and sexually health) clinic. They had been illicit drug free for over a year and were undertaking Subutex (Buprenorphine) detoxification with the eventual plan of becoming drug free by delivery.

Marion has a 13-year old daughter who lives with Marion’s mother and has started to visit her over the weekends.

Marion books early with this pregnancy and accesses routine antenatal care. Her pregnancy is complicated by a positive hepatitis C result (HCV) RNA positive. She also requires help with her accommodation as she lives in a single room ‘bedsit’.

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Case study 2 

Anna is a pregnant 34-year old woman with a history of three previous vaginal births including a twin pregnancy 12, 10 and 6 years ago. Her children have all been placed for adoption, having been removed from her care by the Local Authority after each subsequent birth. Anna is a chaotic drug user, injecting heroin and crack cocaine daily. Her substance misuse is funded through prostitution and suspected criminal activity. She is homeless and has limited social support. She accessed the specialist midwife early at 7 weeks gestation and insists that she can make the lifestyle changes she will require to enable her to parent successfully. She is aware there will be a Children’s Services referral made. There are no medical issues with Anna however she has a co-existing mental health problem which impacts on her compliance with both treatment services and the support services.

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Substance misuse and pregnancy outcomes 

The impact of perinatal drug exposure is difficult to assess because many factors have an impact on pregnancy outcomes and childhood development. Although the British national formulary cautions that ‘any drug can have a harmful effect on the fetus at anytime in pregnancy’, the reality is that few drugs in common use have a direct impact on pregnancy. It is difficult to disentangle the contribution of genetic and environmental factors (smoking, drinking, poor nutrition, stress, violence and poverty) from the effects of illegal substance misuse. The long-term effects of drug use during pregnancy are even more difficult to detect, as longitudinal studies are complex and expensive to undertake.

Witton and Best have reviewed three decades of research on prenatal drug exposure.

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Management of the pregnant drug user 

Data from the UK Advisory Council on the Misuse of Drugs suggest that there are 6000 births to problem drug users each year (1% of all UK deliveries). These women may have serious uncertainties about their pregnancy, and anxiety about how they will be treated by maternity services, drug services, and social and primary care because of their drug use. The pregnancy is often unplanned, as many opiate users are amenorrhoeic or lead lives too chaotic for regular and effective use of contraception. This may delay presentation to antenatal services and therefore heighten the risks to the pregnancy. Community-based multidisciplinary care should be knowledgeable and non-judgemental and include a midwife specialized in substance misuse. These teams can help to improve compliance and should facilitate access to the wide variety of services needed by these women. They should encourage drug-using women to engage early in pregnancy with sexual health and/or hospital-based maternity services. Although women with drug and/or alcohol problems have potentially high-risk pregnancies, and their pregnancy care should be obstetrics led, much can be coordinated and delivered by community midwives.

Many opiate users have already engaged with drug treatment services and have been prescribed methadone as an opiate substitute. Methadone has a stabilizing effect in that it reduces the need to drug-seek, drug-use and commit crime, giving women time to re-address their lifestyle, improve their social circumstances and maintain contact with agencies. Methadone has a long half-life and during pregnancy is taken once daily. The aim is to reduce episodes of opioid withdrawal and thereby reduce the risk of preterm labour associated with chaotic heroin use. Methadone can be prescribed as a maintenance dose or as a planned reduction throughout pregnancy. Although some authorities believe that pregnant women can detoxify from opiates/methadone potentially rapidly at any stage of pregnancy without ill effect, most services withdraw, stabilize or increase methadone at a slow pace throughout pregnancy according to the woman’s ability to cope, reducing or eliminating the need for illicit heroin use. Buprenorphine is increasingly used as an opiate substitute, particularly in less chaotic substance misusers, and appears to be similar to methadone in its benefits and disadvantages. Withdrawal may be accomplished more quickly with buprenorphine than with methadone, though this has not been tested in pregnancy.

Women should be advised to stop using cocaine during pregnancy to reduce the risk of obstetric accidents. There is no evidence that substitution with benzodiazepines is helpful in pregnancy and the aim should be to slowly reduce levels of cocaine consumption to prevent maternal convulsions.

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Antenatal care 

As part of the routine enquiry during antenatal booking, midwives are trained to ask all women about their medical and obstetric history, any social concerns or child protection issues, alcohol, smoking or substance misuse history, any history of domestic violence, and any history of mental health issues. Women with a history of substance misuse are referred to obstetrics-led specialist clinics with access to the specialist midwife. A priority referral to the drug service is made for women who are still using and are not already in treatment, and also for their partner. Routine dating and detailed scans are offered and further growth scans can be organized as required.

Drug-using women are offered screening for HIV, hepatitis B virus (HBV) and syphilis, as are all pregnant women in the UK. HCV testing is offered with counselling to women with a current or past history of intravenous substance misuse. Although the prevalence of HIV has increased among drug users in the UK, it remains low outside London. Approximately one-third of intravenous substance misusers are HBV positive, but there is a good uptake of HBV vaccination for at-risk newborns. Babies born to HBV surface antigen-positive women should receive active immunization within 24 h of birth, and babies of women who are e-antibody negative should also be given passive immunization with immunoglobulin at birth. Some regions immunize pregnant women with HBV vaccine during pregnancy as it provides an opportunity for sustained contact with healthcare services. The prevalence of hepatitis C is as high as 50% among intravenous drug abusers in some geographical areas. Women known to be HCV carriers should undergo serology and a PCR test to assess the level of viraemia. No interventions have been shown to reduce vertical transmission of HCV (4–6%), though this is rare in non-viraemic (PCR-negative) women. Caesarean section is reserved for those with co-existing HIV Infection, or other obstetric indications, and breast-feeding is encouraged.

Sexual health screening should be offered to pregnant substance misusers. In the UK, syphilis is routinely screened for on the booking blood sample; this is vital as 70–100% of infants become congenitally infected if the infection is left untreated. A second sample is usually taken to confirm the result. Help with interpretation of the serology results should be sought from a genitourinary medicine specialist if they are thought to indicate past, treated syphilis or previous infection with a different treponeme. Syphilis should be treated with intramuscular penicillin, or oral erythromycin if the woman is allergic. Screening for chlamydia from a urine sample is often routinely available, and screening for both chlamydia and gonorrhoea can be offered on referral to the genitourinary medicine department. Repeat screening for these infections should be considered in the third trimester, even if the booking samples were clear. This is particularly the case in women who are sex-workers.

Intravenous access is often a problem in women with a long history of intravenous drug abuse, and obstetric anaesthetic involvement may be advised. Other medical conditions resulting directly or indirectly from substance misuse (e.g. anaemia, cardiac valve dysfunction) must be addressed, possibly with the help of a physician or maternal medic.

With regards to mental health there are high rates of psychiatric disorders among individuals misusing drugs and/or alcohol. These patients present with a range of problems and disorders (anxiety, mood changes). Others have ‘personality disorders’, some with significant personality traits that may negatively impact upon their presentation and compliance with treatment. Patients with co-existing mental health and drug/alcohol misuse problems are regarded as having ‘dual diagnosis’ (co-morbidity). Women with co-morbidity issues are also likely to have complex contributing factors such as high relapse rates, self harm episodes, housing instability, poor levels of social functioning, violence, criminality, and social isolation.

Individuals identified in pregnancy with severe mental health problems should be referred as usual to the Perinatal Mental Health Team who will then liaise with the Secondary Alcohol and Drug Services.

Those individuals already managed by Mental Health Teams will be assessed by their practitioners, and appropriate referral and treatments organized.

Referrals and contact can also be made to the Specialist Midwife in Substance Misuse for advice and support (DH 2007).

Although drug use itself does not necessarily cause child protection issues, it is often associated with socioeconomic deprivation and other factors that may affect parenting capacity. Therefore, it is good practice that all pregnant drug users receive multidisciplinary management that addresses their social needs. A multi-agency planning meeting held by the 32nd week of pregnancy allows identification of actual or potential problems and social care (child protection) referrals can be made before birth.

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Intrapartum management 

Pregnant drug-using women who have stabilized their drug use and accessed regular antenatal care are likely to deliver spontaneously at term. Although often a cause for concern, opiate analgesia can be offered as in any other woman, as methadone in this context is not a substitute for routine analgesia. Women medicated with buprenorphine may find opiate analgesia ineffective because it contains both opioid agonist and opioid antagonist properties. The on-call anaesthetist for the labour suite should be alerted when a woman with poor venous access is admitted.

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Postpartum management 

After delivery, babies should go to the postnatal wards with their mother unless there is a medical reason for admission to the neonatal unit.

There is often concern about neonatal abstinence syndrome (NAS) in the newborns of opiate users. NAS is defined as a general disorder that presents with CNS hyperirritability, gastrointestinal dysfunction, respiratory distress and vague autonomic symptoms. Recent studies have suggested that the problems experienced by infants born to opioid-dependent mothers are sometimes drug-related NAS, but most are due to harm associated with a substance misuse lifestyle (intoxication, withdrawal, poverty, inadequate self-care). Most heroin users also smoke cigarettes, which can add to the symptoms of withdrawal. Infants exposed to opioids are difficult to console, while their mothers often have a history of poor parenting skills, low self-esteem and limited social support, which may lead to difficulties with mother-infant attachment and bonding. NAS should be treated by non-pharmacological supportive care initially and the mother should be encouraged to swaddle, parent, feed and nurture the infant to settle it. Some regions use an abstinence score chart as a tool to aid assessment and observation by staff and parents. In 2005, a Cochrane review found little evidence to suggest that pharmacological treatments were any more successful than supportive care for the neonate, but they prolonged hospitalization and subjected the infant to exposure to drugs that may not have been necessary. In 1998, the American Academy of Paediatrics suggested that the decision to use drug therapy must be individualized depending on the severity of the withdrawal signs, but pointed out that pharmacological management of NAS risks compounding the deficits induced by intrauterine exposure to these drugs. In addition, removing a baby from its mother at the time of birth potentially negatively influences the bonding process, increases the mother’s feelings of guilt and loss of control, and reinforces the maternal perception that discomfort or annoying behaviour should be treated with drugs. Awareness of NAS may increase the possibility that other medical conditions that produce similar behaviour (e.g. hypoglycaemia, CNS haemorrhage, infection) may be missed.

Although drug use should be stable for breast-feeding to be appropriate, successful establishment of breast-feeding is adequate evidence of stability. Breast-feeding should be encouraged, as the benefits to the baby far outweigh any risks. Breast-feeding with HIV infection requires specific counselling and advice, but there is no risk from HBV provided immunization has been given. Breast-feeding is not contraindicated in HCV carriers.

Contraceptive advice should be offered to all drug-using women during the postnatal period with a focus on long-acting injectable contraceptives, implants and the intrauterine progestogen coil.

Marion (case 1) was referred to the local pregnancy and substance misuse clinic, led by a specialist midwife and an interested obstetrician. Marion became drug free by 20 weeks gestation but continued to work with her drug worker around ‘relapse prevention’ for the remainder of her pregnancy. She was referred to the specialist hepatologist with regards to her hepatitis C and follow-up testing of the baby was organized before discharge. She was referred for tenancy support to address her housing issues. Marion did not present any safeguarding concerns and her care was managed predominately by universal services.

Anna (case 2) accessed all her antenatal care. She was prescribed 70 ml methadone daily but despite regular input from the drug service she did not stop injecting drugs until 32 weeks gestation. She failed to acknowledge the potential harm on both her own health and the baby’s. She did not comply with any other agency and remained homeless. She and her partner (also a drug user who did not access any drug treatment) struggled to budget for their basic needs and their personal hygiene became very poor. Anna did not acknowledge her mental health problems and declined all referral to the Consultant Psychiatrist at the Secondary Alcohol and Drug service. An initial Child Protection Conference was held and baby was subject to a care plan under the category ‘at risk of neglect’. Baby was placed in foster care on discharge from hospital.

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Case study 3 

Case 3 

Val is a 27-year old woman with a history of alcohol dependence. Four years previously she had been subject to a serious sexually assault in her own home and had been drinking daily ever since. This was a planned pregnancy with a new partner, however Val was frightened to discover when she tried to cut down her drinking she had severe ‘shakes’ and over whelming feelings of anxiety and panic. Following a booking appointment at her local health centre she is referred to the specialist midwife in substance misuse.

At the first appointment Val admits to drinking over 100 units per week of 5% cider 500 ml cans. She drinks throughout the day alone in her home. She says she no longer gets drunk. Her son, now 10, has been with Val’s mother over the last 4 years having been removed by social services due to Val’s neglect and prioritization of her drinking behaviour. She had never accesses alcohol treatment services. She is prescribed Citalopram 20 mg by the GP for her ‘anxiety’ and this medication is continued throughout the pregnancy.

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Women and alcohol 

In recognition of the dangers of excessive drinking, the Department of Health issued guidance in 1995 suggesting a maximum intake of 2–3 units per day for women, with two alcohol-free days per week. Pregnant women were recommended to drink less than this or nothing at all. Recent government figures report that 33% of young British women (under 25 years) exceed the sensible weekly limit and, overall, 5% of women are ‘problem drinkers’; that is, they experience problems of psychological and/or physical dependence. Recent studies have found that many young women who have recently become sexually active use alcohol before intercourse, and a large number drink enough to compromise their ability to use contraceptives, resulting in unplanned pregnancies. Women have been drinking more in recent decades as their role in society has changed and they have more opportunities to drink than previously. Women’s drinking has become socially acceptable, and many women have a higher disposable income and fewer family responsibilities.

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Alcohol in pregnancy 

Alcohol consumption during pregnancy is a highly emotive subject. Some believe that pregnant women should abstain from alcohol consumption; others believe that alcohol consumed in moderation has no significant harmful effects. The antenatal guidelines published by the UK National Institute for Health and Clinical Excellence in 2008 state that ‘If women choose to drink alcohol during pregnancy they should be advised to drink no more than 1–2 UK units once or twice a week’. Similarly the Royal College of Obstetricians and Gynaecologists Green-top guideline favours drinking no more than one or two units of alcohol once or twice per week.

Maternal alcohol consumption during pregnancy is associated with various neurological abnormalities and functional impairments in the offspring. Alcohol is teratogenic and can directly induce developmental abnormality. In 1973, Jones and Smith identified a pattern of abnormalities that occurred in children born to mothers who were problem drinkers and coined the term ‘fetal alcohol syndrome’. A more recent term is ‘fetal alcohol spectrum disorder’ (FASD) (Table 2), which includes milder versions of FAS and isolated alcohol-related birth defects. It is widely recognized that many of these go unnoticed and unrecorded. FAS is said to be the greatest cause of non-genetic mental disability in the Western world and the only one that is 100% preventable.

Table 2. Fetal alcohol spectrum disorder

For the diagnosis of fetal alcohol syndrome, there must be confirmed maternal alcohol exposure.

The correlation between FAS and the extent of alcohol misuse in pregnancy is poor, with only 1/20 heavy drinkers delivering babies with evidence of FASD. It is likely that other factors are critical in the expression of this syndrome, such as social and nutritional status. There is also a correlation between alcohol use and cigarette smoking, and the latter is a well-recognized cause of, and contributor to, intrauterine growth restriction. FAS is more common in the offspring of socially disadvantaged women, who experience many other risk factors for adverse pregnancy outcomes such as co-morbid psychiatric disorders and family problems. The interaction between a vulnerable pregnancy and a disadvantaged environment compounds the negative outcome for the fetus.

All pregnant women should be asked at booking about their alcohol consumption. Individuals are most likely to be open about their drinking when they understand that the information is being collected to help them, that it is confidential, and that giving accurate information will improve their care. Fear that the information will be used in a punitive way inhibits honest answers. The first stage, therefore, is to establish a good therapeutic relationship and to explain the reason for this interest in the woman’s drinking. Several screening tools are available to assess the likelihood of a drinking problem, but in essence they all cover similar ground. There is nothing complicated about assessing someone’s drinking pattern. Useful questions are listed in Table 3.

Table 3. Questions used when assessing alcohol dependence

Simply raising the subject of alcohol consumption may have an impact on a pregnant woman’s drinking habits. Many women, rather than adopting a regular drinking pattern throughout pregnancy, are more likely to drink heavily around the time of conception, before realizing they are pregnant, and reduce or stop drinking later in pregnancy. Some women reduce drinking because they are aware of problems, or eliminate alcohol from their daily routine because of taste aversion or nausea. It is uncommon for a woman to start drinking heavily in the middle or at the end of pregnancy. Brief interventions, in the form of information giving, and providing patients with an opportunity to consider the positives and negatives of their drinking behaviour, have been shown to noticeably reduce alcohol consumption.

Women with a drinking history should be referred for obstetrics-led care, ideally supported by a dedicated midwife with a special interest in substance misuse. Regular growth scans are indicated and may help to entice the client into an antenatal clinic. If the woman is not already in treatment, a referral to the alcohol and drug service should be considered. A multi-agency support package can be constructed that addresses her social and medical needs, allowing identification of actual or potential problems and referral to other agencies as required. Significant hepatic, cardiac or haematological dysfunction secondary to longstanding alcohol abuse necessitates specialized care from a maternal medic or a physician with an interest in pregnancy.

Pharmacological treatment and supervised withdrawal for the physically dependent pregnant mother is known as detoxification. This should generally take place in an inpatient setting with collaboration between the obstetrician and the alcohol service. Patients who are physically dependent on alcohol should always be advised to avoid sudden cessation of alcohol consumption, and in pregnant women there is the additional threat to the life of the fetus. Differentiation of symptoms of alcohol withdrawal from symptoms of pregnancy may be difficult, but tremor and fever are usually specific for alcohol withdrawal. Uncontrolled withdrawal risks agitation, tachycardia, seizures, hypertension and fetal death. Chlordiazepoxide, or less commonly diazepam, is used in a graduated reduction regimen to reduce the risks associated with detoxification.

Alcohol is not stored in breast milk, but its level parallels that in the maternal blood. Breast-feeding should be encouraged as less than 2% of the alcohol dose consumed by the mother reaches her milk. Alcohol may disrupt lactation and diminish milk supplies and women should be advised to keep their drinking to a minimum while lactating. Contraceptive advice should be offered to women with a drinking history during the postnatal period to avoid unplanned pregnancy.

Despite her drinking behaviour, Val (case 3) accessed antenatal care via the specialist midwife and maternity unit. Although her scans showed no abnormalities the fetal growth appeared compromised from 32 weeks gestation and plotted below average on the centiles. She was referred initially to a specialist alcohol service offering 6 weeks brief and extended advice and thereafter to the Secondary Drug and Alcohol Service. Her liver function tests showed no abnormalities and she reduced her alcohol units by half. However she still continued to drink by the time her baby was born. At birth at 37 weeks gestation the baby was severely growth retarded at 1.5 kg but showed no obvious features of FAS. Baby gained weight rapidly and mother and baby were discharged together with input from a multi-agency support package based around The Common Assessment Framework (CAF).

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Further reading 

1. Advisory Council on the Misuse of Drugs . Responding to the needs of children of problem drug users. Hidden harm. 2003;www.drugs.gov.uk
2. Department of Health (DH) . Drug misuse and dependence UK guidelines on clinical management. www.nta.gov.uk2007;
3. Department of Health . Alcohol misuse interventions. Guidance on developing a local programme of improvements. National Treatment Agency for Substance Misuse; 2005;http://wwwdh.gov.uk/publications
4. Health Protection Agency. Shooting up. Infections among injecting drug users in the UK 2008. Update October 2009.
5. http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1195733837406
6. Hepburn M. Substance misuse in pregnancy. Curr Obstet Gynaecol. 2004;14:419–425
7. National Institute for Health and Clinical Excellence . Antenatal care: routine care for the healthy pregnant woman. March 2008;
8. http://www.nice.org.uk/nicemedia/pdf/CG62FullGuidelineCorrectedJune2008July2009.pdf
9. Royal College of Obstetricians and Gynaecologists . Alcohol and pregnancy – information for you. Alcohol consumption and the outcomes of pregnancy. RCOG Statement No. 5 – March 2006. 2006;www.rcog.org.uk/index.asp?PageID=1816
10. Royal College of Obstetricians and Gynaecologists . The Confidential Enquiry into Maternal and Child Health (CEMACH). www.cemach.org.uk2004;
11. Witton J, Best D. Families, maternal drug use, prenatal drug exposure and later drug use: a review of the literature. In: Pathways to problems. Advisory Council on the Misuse of Drugs; 2006;www.drugs.gov.uk